Abstract: Benzoyl N-Acetyl-D-Glucosamine (NAG) ester was synthesised based on NAG and benzoyl chloride. The chemical structure of the products were characterized by FT-IR, LC-MS. The solubility, thermal stability and antibacterial activity were also studied. Research showed that the tri-ester was synthesized with the molar ratio of reagents at 4:1 (benzoyl chloride/NAG) under the reaction temperatureat at 0℃ for 3h. The benzoyl NAG ester had good solvability in various organic solvents and the melting temperature was about 171~175℃. Moreover, the antibacterial activity was concentration-dependent and varying pH had little effect on antibacterial activity. The inhibitory experiments showed that benzoyl NAG ester had significant effect against the growth of microorganisms under the pH rang from3.5 to 7.5.The minimum inhibitory concentration (MIC) of benzoyl NAG ester against E. coli, staphylococcus aureus, beer yeast, aspergillus Niger were 2.4~2.6, 1.4~1.6, 2.0~2.2, 1.8~2.0 g/L, respectively.